Fix default argument conversion failure and SFINAE.

	* call.c (build_over_call): Check convert_default_arg result for
	error_mark_node.
	* parser.c (cp_parser_late_parsing_default_args): Remember
	error_mark_node.

From-SVN: r251421

gcc/cp/ChangeLog

+2017-08-29  Jason Merrill  <jason@redhat.com>
+
+	Fix default argument conversion failure and SFINAE.
+	* call.c (build_over_call): Check convert_default_arg result for
+	error_mark_node.
+	* parser.c (cp_parser_late_parsing_default_args): Remember
+	error_mark_node.
+
 2017-08-28  Nathan Sidwell  <nathan@acm.org>
 
 	* cp-tree.h (lang_type): Replace sorted_fields vector with

gcc/cp/call.c

@@ -7892,10 +7892,13 @@ build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain)
     {
       if (TREE_VALUE (parm) == error_mark_node)
 	return error_mark_node;
-      argarray[j++] = convert_default_arg (TREE_VALUE (parm),
-					   TREE_PURPOSE (parm),
-					   fn, i - is_method,
-					   complain);
+      val = convert_default_arg (TREE_VALUE (parm),
+				 TREE_PURPOSE (parm),
+				 fn, i - is_method,
+				 complain);
+      if (val == error_mark_node)
+        return error_mark_node;
+      argarray[j++] = val;
     }
 
   /* Ellipsis */

gcc/cp/parser.c

@@ -27645,11 +27645,6 @@ cp_parser_late_parsing_default_args (cp_parser *parser, tree fn)
 	= cp_parser_late_parse_one_default_arg (parser, parmdecl,
 						default_arg,
 						TREE_VALUE (parm));
-      if (parsed_arg == error_mark_node)
-	{
-	  continue;
-	}
-
       TREE_PURPOSE (parm) = parsed_arg;
 
       /* Update any instantiations we've already created.  */

gcc/testsuite/g++.dg/ext/is_constructible1.C

+// { dg-do compile { target c++11 } }
+// { dg-options "" }
+
+template<class T> struct Foo { Foo(T = nullptr) {} };
+
+static_assert (!__is_constructible(Foo<int>));

gcc/testsuite/g++.dg/other/new1.C

@@ -10,5 +10,5 @@ struct A
 
 void foo()
 {
-  new A;	// { dg-error "default argument" }
+  new A;
 }

gcc/testsuite/g++.dg/parse/crash40.C

@@ -37,6 +37,6 @@ void bar()
   int i;
   i.C::foo<0>(); /* { dg-error "which is of non-class type" } */
 
-  S<false> s; /* { dg-error "default argument" } */
+  S<false> s;
   SS<false> ss;
 }

gcc/testsuite/g++.dg/parse/defarg12.C

@@ -9,5 +9,5 @@ struct A
 
 void foo()
 {
-  A().i; /* { dg-error "default argument" } */
+  A().i;
 }

gcc/testsuite/g++.dg/template/error15.C

@@ -18,7 +18,7 @@ protected:
 
 template <class T>
 void B<T>::g(void) {
-  f(); // { dg-error "default argument" }
+  f();
 }
 
 template class B<long>;